Quantitatively, evaluate the moment of inertia of a hoop about an axis in the plane of the hoop passing through the center of the hoop (neutral axis contains the centroid if no net tension or compression of the beam exists) with a mass M. Then evaluate the same moment for a solid circle of equal mass. This geomtery is easy to evaluate. Qualitatively, you can compare the radius of gyration of the two cross sections about the neutral axis. What do you conclude about their moments? How is bending related to moment or radius of gyration?